In software testing, there are three different types of testing depending on how much knowledge the testers have on the software being tested.

White Box Testing

• With full knowledge of the software. (internal structures, source codes, etc.)
• Usually tests how the software performs.
• Suitable for software developers.

Black Box Testing

• Without having any knowledge of the software. (internal structures, source codes, etc.)
• Usually tests for functionality of the software.
• Suitable for third-party testers.

Gray Box Testing

• Test with partial knowledge of the software.